great advice and info, does each business need it's own sales tax #,
(ca.) or can they share one number as divisions of the same
corporation?

Visit your local chamber of commerce.  They will have all the
information you need or you can simply cal them.  Best of all it's
free!

As long as the division is still within the same legal structure of
the company you would get just one resell number (permit).

That is, if the money you receive for each division is still received
by the parent corporation and deposited in the parent corporations
bank account you only need one resell permit.

If you want the official information visit the government agency
responsible for the issuance of Resell Permits. This is the California
State Board of Equalization. In San Jose, there is one downtown on
Second Street across from Federal building.

- James